Dual filter and method of making

ABSTRACT

A dual filter apparatus and a process of making a dual filter apparatus that minimizes disruption to the normal flow pattern through the filter apparatus by forming a porous medium suitable to carry a fluid activator and placing an activator proximate the porous filter medium for in situ fluid treatment and removal of debris from the fluid by screening action of the porous filter medium that entraps debris thereon.

FIELD OF THE INVENTION

[0001] This invention relates generally to a dual filter system andapparatus and, more specifically, to a filter carrying an activator toenable the filter to simultaneously and in situ treat the fluid as thefluid flows through the filter while minimizing disruption to the normalflow of fluid through the filter system.

CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application is a continuation in part of my co-pendingpatent application Ser. No. 09/550,668; filed Apr. 17, 2000; titled DualFilter and parent provisional patent application 60/130,468 titled DualFilter and Method of Making, filed Apr. 22, 1999.

BACKGROUND OF THE INVENTION

[0003] In water treatment systems it is known that activators such asbacteria killing materials comprising metal ions are effective inkilling bacteria. One commonly used metal ion is the silver ion andanother commonly used bacteria killing and material is the zinc ion.Other types of ions are used as algaecides. The difficulty in use ofmetal ions is to maintain the ion concentration within proper rangessince too low metal ion concentration results in ineffective killing ofbacteria and to high metal ion concentrations can be harmful. Anotherdifficulty is to be able to controllable release the materials toprovide for water purification over an extended period of time.

[0004] It has been demonstrated that a single bacteria killing materialthat releases silver ions can be effectively used to kill bacteria inwater systems such as spas, hot tubs and swimming pools over an extendedperiod of time. In some cases multiple bacteria killing materials thatreleases both ions of silver and zinc are used to kill bacteria over anextended period of time.

[0005] In one embodiment of a bacteria killing material I use anadhesive that is securable to both a metal ion generating material andto a particle carrier that is placed in a container within the watersupply. Water is allowed to flow through the container as the bacteriakilling material controllable release metal ions to kill bacteria in thewater. While the use of bacteria killing materials that release metalions is known, the present invention is directed to the structure andmechanism for holding the bacteria killing materials so as not tointerfere with the release of the bacteria killing materials such asmetal ions without disrupting the normal flow of water through thesystem.

[0006] In most recirculation systems such as for swimming pools, spasand hot tubs a filter is included that removes unwanted waste particlesfrom the water. In one embodiment, which is shown in U.S. Pat. No.4,780,197 a container is placed in the core of the filter. The containeris filled with a bacteria-killing material such as chlorine or bromine.In this type of arrangement one can provide for removal of wasteparticles as well as killing of bacteria in the same part of the system.While this type of system brings the bacteria killing and waterpurification into the filter housing it does not provide for in situkilling of bacteria and removal of debris. However, more importantly,devices placed in the core of the filter create obstructions to normalflow through the fluid filter. The first obstruction to normal flow isthe container itself that hold the bactericide and the secondobstruction to normal flow is the materials that are placed in thecontainer. In the present invention the obstruction to normal flow ofwater through the filter system is substantially eliminated as thebacteria killing material is either secured directly to the filtermedium or to a portion of the filter where the flow area is generallythe largest thereby allowing one to maintain the normal flow patterns ofthe filter mechanism.

[0007] In the present invention, a water treatment composition, forexample, a water purification material, such as a bacteria killingmaterial is secured to a replaceable filter that normally removes debrisfrom the water. With the present invention the replaceable filterperforms a dual in situ function in that the filter simultaneouslyremoves debris and kills bacteria. Consequently, when the filter isreplaced due to accumulation of debris thereon the bacteria killingmaterial is replaced in the same operation thus minimizing the consumermaintenance in maintaining a water system in proper condition. Thus thepresent invention becomes consumer friendly as the need for maintenanceof the system can be reduced.

[0008] In one embodiment of the dual filter apparatus of the presentinvention, a bacteria killing material is affixed directly to fibersthat are formed into a filter medium with the fibers formed into anetwork for screening removal of debris from the water. As water isdirected through the filter medium formed from the fibers containing thebacteria killing material the filter medium traps debris thereon, whilethe bacteria killing material kills bacteria thereon. In this embodimentthe dual filter apparatus simultaneously accomplishes the in situ taskof both filtering debris from the water and killing bacteria as thewater passes through the filter. Other embodiments and refinement of theinvention are described herein. The preferred embodiment is described inrelation to a water purification material comprising a bacteria killingmaterial and other water purification materials such as algaecides,clarifiers or pH adjusters can be used with the present invention.

SUMMARY OF THE INVENTION

[0009] Briefly, the present invention comprises an in situ fluidtreatment system comprising a dual filter having a porous medium forremoving debris and an activator retained proximate the porous mediumfor treating the fluid while minimizing obstruction to normal flowthrough the system as well as a process of making a water purificationdevice by dispersibly securing a bacteria killing material proximate afilter medium for removing debris.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a perspective view of a carrier such as zinc pellethaving a matrix carrying a silver yielding ion thereon; and

[0011]FIG. 2 is a sectional view taken along lines 2-2 of FIG. 1 to showthe adhesive matrix located around the zinc pellet;

[0012]FIG. 3 is a perspective view of a cartridge filter of the presentinvention;

[0013]FIG. 4 is a cross-sectional view of the filter of FIG. 1 takenalong lines 4-4 of FIG. 3;

[0014]FIG. 5 is a side view of a portion of a filter medium without abacteria-killing material thereon;

[0015]FIG. 6 is a front view of the portion of the filter medium of FIG.5;

[0016]FIG. 7 is front view of a portion of the filter medium of FIG. 6with a bacteria killing material secured thereto;

[0017]FIG. 7A is a front view of a portion of a filter medium having apurification material secured directly to the fibers by a thin film ofnon-water soluble porous adhesive;

[0018]FIG. 8 is a partial schematic view of a system for manufacturingfilter medium;

[0019]FIG. 8A is a partial schematic view of an alternative system formanufacturing a filter medium;

[0020]FIG. 9 is a top view a filter cartridge;

[0021]FIG. 10 is a sectional view taken along lines 10-10 of FIG. 9 toshow the invention of a filter with a bacteria killing material locatedtherein;

[0022]FIG. 10A is similar to FIG. 10 but with the annular carrier insertengaging the exterior surface of the core;

[0023]FIG. 10B is similar to FIG. 10 but with the annular carrier insertengaging the exterior surface of the cartridge;

[0024]FIG. 11 is a perspective view of a filter sleeve that has beenformed from a single piece of cloth with the filter stitched and sonicwelded into an annular shape;

[0025]FIG. 11A is a perspective view of a porous annular filter sleeve;

[0026]FIG. 12 is an exploded pictorial view of a filter cartridgehousing contain a bacteria-killing material;

[0027]FIG. 13 is partial schematic view of a dual filter system forsimultaneously removing debris and killing bacteria;

[0028]FIG. 14 shows a partial cross-sectional view of a water filtercartridge having a steel-wool pad-like carrier located within thecartridge core;

[0029]FIG. 15 shows a cross-sectional view of a water filter cartridgehaving a solid core carrier located within the cartridge core;

[0030]FIG. 16 is a pictorial exploded view of a filter medium having ahollow core containing a purification material and located within theinterior of the filter medium;

[0031]FIG. 17 is a partial cross-sectional view of a filter mediumhaving a purification material located within the interior of the filtermedium;

[0032]FIG. 18 shows a partial cross-sectional view of a filter mediumhaving a plurality of elongated members containing water purificationmaterials secured to the interior surface of the filter medium;

[0033]FIG. 18A shows a perspective of a pleated filter medium having aplurality of elongated members containing water purification materialssecured to the exterior surface of the filter medium;

[0034]FIG. 19 shows a partial cross-sectional view of a filter mediumhaving an adjustable water purification material dispenser secured tothe interior surface of the filter medium;

[0035]FIG. 19A shows a close-up view of the adjustable waterpurification material dispenser of FIG. 19;

[0036]FIG. 19B shows an alternative embodiment of a water purificationmaterial dispenser;

[0037]FIG. 20 shows filter medium having a dispenser secured to theinterior surface of the filter medium and the cartridge core coated witha water purification material;

[0038]FIG. 21 shows a mesh screen coated with purification materialsengaging the exterior surface of a filter medium; and

[0039]FIG. 22 is a pictorial exploded view showing a filter mediumhaving an annular sleeve engaging the exterior surface of the filtermedium.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040] In the invention described herein, one forms an in situ waterpurification system comprising a water treatment composition and afilter medium suitable for inserting into a water supply to both killbacteria therein and to screen debris from the water. In one embodimentthe water treatment composition comprises a carrier and a metal ionyielding material, which is secured to a filter medium. Attached to thecarrier is a bacteria killing material which, in the preferredembodiment, comprises silver chloride (AgCl) coating located thereon.The silver chloride particles are suspended in an adhesive matrix thatadhesively secures the silver chloride particles proximate thereto in anion yielding relationship. Another suitable metal ion yielding materialsuitable for use is zinc.

[0041] The bacteria killing material is preferably a metal ion yieldingmaterial although other materials could be used if the materials can bemaintained in active mode over an extended period of time. An example ofsilver ion yielding material is silver chloride, which is described morefully in my co-pending application Ser. No. 08/957,265, filed Oct. 24,1997, titled Water Treatment Composition. Silver chloride is a whitepowder that can be melted or cast like a metal, and is derived fromheating a silver nitrate solution and adding hydrochloric acid or saltsolution to produce a silver chloride solution, which is then boiled orfiltered either in the dark or under a ruby red light to produce thesilver chloride powder. In one embodiment of described process, thesilver chloride while still in solution is combined with an adhesive toform an adhesive silver chloride solution. The adhesive and the silverchloride solution are then applied to a carrier such as a pellet. Theadhesive is then cured to produce a pellet having a silver chloridecoating adhesively adhered thereto with both the zinc and the silverchloride available for reacting with the chemicals within a bacteriacell to kill or damage the bacteria.

[0042] In a preferred embodiment of process, the silver chloride whilestill in solution is combined with an adhesive to form an adhesivesilver chloride solution which is applied directly to a filter materialfor use in screening waste particles from a water source. The termadhesively secured herein is meant to include a surface attachmentstructure that does not prevent the bacteria tilling materials fromreleasing the ions to kill unwanted bacteria.

[0043] Referring to FIGS. 1 and 2, there is shown one way of forming awater treatment pellet 10 having an adhesive matrix coating 12. Adhesivematrix coating 12 comprises an adhesive that secures itself to thesurface of both the silver ion generating material, which comprisessilver chloride 13 and to the carrier, which is shown as a pellet 11.The process is described in relation to forming a silver chloridecoating on a pellet so that the silver ion remains in a reactive stateto react with the chemicals in the bacteria and effectively damage orkill the bacteria. However, the carrier 11 could be an active carrier,such as zinc as multiple ions generating material may be suitable forkilling different types of bacteria.

[0044]FIG. 2 is a cross-sectional view of the silver chloride coatedpellet 10 of FIG. 1 showing carrier particle 11 centrally located withinadhesive matrix 12 that contains silver chloride 13 dispersed throughoutthe adhesive matrix 12. As can be seen from the drawing, the silverchloride 13 is maintained in the water porous matrix proximate thecarrier pellet 11 to enable water to contact both the silver chloridelocated within the matrix. These types of pellets 11 can be placeddirectly into a container in the water to allow the bacteria killingmaterials to be released into the water. In one embodiment of thepresent invention the pellets containing the bacteria killing materialsare secured directly to a filter medium so that the bacteria killingmaterials controllable release metal ions over an extended period oftime.

[0045] In the embodiment shown in FIG. 2 one coats a carrier particlewith a silver ion yielding material such as silver chloride byadhesively affixing or securing the silver chloride to the carrierthrough a non-soluble water porous adhesive matrix. A suitable materialfor adhesively securing the silver chloride proximate the carrier iscommercially available gelatin which can be cross-linked with an aqueoussolution of formaldehyde or glutaraldehyde to form a non-soluble, waterpenetrable matrix on the exterior surface of the carrier. Other suitablenon-soluble water porous adhesive matrixes are polyvinyl acetate,polyurethane, epoxy resin, polyvinyl alcohol and polyvinyl acetate.

[0046] In the process of forming individual carriers for the iongenerating materials, one forms a plurality of carriers or watertreatment members typically an ⅛ inch or smaller which are suitable forinserting into an inline feeder. Instead of placing the individualcarriers into a separate inline feeder the present invention includesthe step of securing the carriers with the ion generating materialdirectly to the filter material used to form a mechanical filter. In thepreferred mode of the invention, the ion generating materials aresecured directly to the fabric or filter medium without the use of aseparate carrier. In both cases one obtains a dual filter system thatprovides for in situ killing of bacteria and removal of debris from thewater flowing through the filter system.

[0047] The following examples illustrate how silver chloride particleswere affixed proximate to the exterior surface of a carrier such as apellet.

EXAMPLE 1

[0048] In order to coat a batch of pellets with an adhesive matrixcontaining silver chloride, 12.5 grams of silver nitrate are mixed in 25ml of distilled water to form an aqueous silver nitrate mixture.

[0049] Next, 1.5 grams of gelatin are mixed in 25 ml of distilled waterto form a gelatin mixture. The gelatin mixture is heated to atemperature of about 140 degrees F.

[0050] To eliminate lumps in the gelatin mixture, the gelatin mixture isthen strained through a screen. At this point, 5 grams of sodiumchloride are mixed into the gelatin mixture. The gelatin mixture is thencombined with the aqueous silver nitrate mixture to convert the silvernitrate into silver chloride to thereby form an aqueous silver chloridegelatin mixture. A batch of pellets having a maximum dimension of about⅛ inch is then heated to about 140 degrees F. The pellets are thensprayed with the heated, aqueous silver chloride gelatin mixture. Inorder to form a matrix to affix the silver chloride to the pellets, thesilver chloride gelatin mixture is then immersed in an aqueous bath ofglutaraldehyde for about 12 hours to react the gelatin with theglutaraldehyde. The curing produce an adhesive matrix that secured thepellets with the silver chloride that is dispersed throughout theadhesive matrix. After curing, the pellets, which are covered with acoating of silver chloride, are rinsed and air dried to produce pelletswith a silver chloride coating affixed proximate to the pellets.

EXAMPLE 2

[0051] The above process was repeated except instead of immersing thepellets with the silver chloride gelatin mixture in an aqueous bath offormaldehyde, the pellets with the silver chloride gelatin mixture werecured in an aqueous bath of formaldehyde.

[0052] In the above examples, the pellets had a maximum dimension ofabout ⅛ of an inch. Larger or smaller pellets could be used; however,for use as a water treatment composition in a dispensing valve, it ispreferred to have carrier in multiple pellets in order to present alarger surface area to the water containing the bacteria. While securingof the bacteria killing material to the pellet carrier has beendescribed the bacteria killing material can also be secured directly tothe filter medium using the same adhesive.

[0053] In the above described method of forming the bacteria killingmaterial, the adhesive used was gelatin as gelatin is capable ofadhering to the surfaces of both the carrier and the silver chloride.That is, gelatin which can be cross-linked in the presence offormaldehyde or glutaraldehyde to obtain the necessary adhesivecharacteristics remains non-soluble in the water and unreactive witheither the carrier or the silver chloride, and thus can hold the silverchloride proximate the carrier. That is the cross-linked gelatin notonly forms a surface attachment but also forms a matrix to support orsecure the silver chloride in proximity to the surface of the pellet. Asthe gelatin matrix is securable to the surfaces of both the silverchloride and to the pellets, one is assured that the silver ion yieldingmaterial will remain proximate each other to generate ions thereof.Also, the gelatin is desirable since the porosity of the adhesive matrixformed from gelatin allows bacteria containing water access to both thesilver to enable both the silver ions to kill the bacteria in the water.

[0054] While gelatin is described as one of the adhesives, othersuitable adhesives for securing the bacteria killing material to eitherthe carrier or directly to the filter material so that the metal ionsare controllable released include polyurethane, epoxy resin polyvinylalcohol and polyvinyl acetate.

[0055] Referring to FIG. 3, reference numeral 20 identifies a dualfilter apparatus of the present invention for simultaneously removingdebris and killing bacteria. The filter 20, which is in cartridge form,includes a first end cap 21 and a second end cap 22 with a porouspleated filter medium 23 secured therebetween for screening wasteparticles from the water as the water flows through the filter medium23. End cap 21 is shown with an opening 21 a for ingress of fluid, andsimilarly FIG. 4 shows that end cap 22 includes an opening 22 a foringress of fluid into the interior 26 within the zigzag shaped filtermedium 23.

[0056]FIG. 5 and FIG. 6 show a portion of one embodiment of a porousfilter medium 30 that is arranged in a cross-hatched pattern to form anetwork comprised of a set of vertical fibers 31, 32 and 33 supporting aset of horizontal fibers 34, 35, 36, 37 and 38 to provide a plurality ofregular openings 39 therein for screening waste particles of larger sizefrom the water. In normal operation of the filter medium 30, water flowsthrough the openings 39 while the large debris particles encounter theexternal network of fibers and is thus prevented from flowing throughthe filter medium 30. In time the filter becomes clogged with wasteparticles and needs to be replaced. In the embodiment of FIG. 5 and FIG.6 the fibers are shown as round with regular shaped openings therein;however, it should be understood that the shape of the fibers, the shapeof the openings as well as the use of non-fibers are suitable for makinga filter for removing water carried debris as the water flows throughthe filter medium.

[0057]FIG. 7 shows the filter medium 30 with a water purificationmaterial such as a bacteria killing material 40 dispersibly secured tothe surface of the filter medium so as to minimize obstruction to normalflow through the filter housing. In the embodiment shown, the bacteriakilling material comprises silver chloride and a pellet acting as acarrier. By securing the bacteria killing material to the fibers of thefilter, one provides protrusions that come into contact with the waterthat flows through openings 39. Note, the obstruction to normal flowthrough the filter is minimized since the material does not require aseparate container nor is the material concentrated in one region of thefilter system. That is, placement of a housing in the core of a filtercreates a restriction in a narrowest portion of the system. In thepresent invention the bacteria killing material is placed in the portionof the system where the volume restriction is the least. That is, thearea of the filter medium is large compared to the flow area through thecore of the filter. Consequently, sufficient bacteria killing materialcan be dispersibly secured to the filter medium or proximate the filtermedium so that the density of bacteria killing material per unit of flowarea of the filter medium is small in comparison to the density ofbacteria killing material which is required if the bacteria killingmaterial is located in the core area of the filter. Thus, debrismaterial which is larger than opening 39 is prevented from passingthrough the filer medium by the network of fibers while the water cominginto contact with the bacteria killing material on the fibers receivesthe bacteria killing action. While only two layers of fibers are shown,it is apparent that multiple layers of fibers can be stacked to providea torturous path for the water to follow thereby increasing the contactbetween the water and the bacteria killing material.

[0058]FIG. 7A shows a portion of the filter medium 60 wherein theseparate carrier for the water purification material such as a bacteriakilling material has been dispensed with. In this preferred mode theportion of the filter medium includes fibrous members 61, 62 and 63 thatintersect with members 64, 65 and 66 to form a plurality of openings 68therethrough. In the embodiment shown the bacteria killing material isdispersibly secured directly to fibers by a thin film of non-watersoluble porous adhesive 70 and 71. The adhesive 70 dispersibly securesthe bacteria killing materials directly to the fibers of the filtermedium in a condition to allow a controlled release of ions. In theembodiment shown, the bacteria killing material is preferably acontrollable releasable ion yielding, material selected from the groupof metal ion yielding materials consisting of zinc sulfate, zinccarbonate, zinc chloride, copper carbonate, copper sulfate, silverchloride, stannous chloride and stannic chloride. Although an adhesiveis described as a carrier for the water purification material the waterpurification can also be formed into film form and secured directly tothe filter medium without the use of a separate carrier such as anadhesive.

[0059] Other ion yielding materials with controllable release includecopper (II) acetate and its hydrates, copper (I) bromide and itshydrates, copper (II) bromide, copper (I) chloride and its hydrates,copper (II) chloride and its hydrates, copper (II) gluconate, copper(II) hydroxide, copper (II) oxide, copper sulfate, zinc acetate and itshydrates, zinc bromide and its hydrates, zinc carbonate hydroxidehydrate, zinc carbonate, zinc chloride and its hydrates, zinc citrateand its hydrates, zinc iodide and its hydrates, zinc nitrates and itshydrates, , zinc oxide, zinc sulfate and its hydrates, silver acetate,silver carbonate, chelated silver ions, silver-exchanged zeolite, silvernitrate, silver oxide, silver sulfate, silver chloride, silver powderand colloidal silver, silver bromide and silver acetate.

[0060] In addition to water purification materials that kill bacteria,other water purification materials such as algaecides, clarifiers oreven pH adjustment materials such as limestone can be carried by thepresent invention to provide the dual action of water screening forwaste particles while simultaneously purifying the water.

[0061]FIGS. 8 and 8A show methods of making a filter medium that cansimultaneously filter out debris while purifying water with twodifferent types of water purification material by placing the waterpurification materials on the fibers before weaving the fibers into afilter structure.

[0062] In the method illustrated in FIG. 8, the filter mediummanufacturing system 50 includes a first station 51 for forming a fiber52 having a plurality of a first bacteria killing materials such as zincparticles 53 secured thereto. A second station 55 includes a secondfiber 56 having a second bacteria killing material such as silverchloride particles 57 secured thereto. The fiber are directed into athird station 58 that weaves the fibers into a porous filter medium 59comprised of fibers with a first bacteria killing material thereon andfibers with a second bacteria killing material thereon which are locatedin proximity to each other to thereby provide the bacteria killingaction from two different bacteria killing materials.

[0063] Although different embodiments are shown, in each embodiment thefilter medium, which normally is used to remove debris from the water byscreening the waste particles, is also used as a carrier for the firstbacteria killing materials and the second bacteria killing materialswhich are dispersibly secured thereon so that water passing through thefilter medium riot only removes debris but also the bacteria is killedby the bacteria killing materials located on the filter medium.

[0064] In the method illustrated in FIG. 8A, the filter mediummanufacturing system 50 a includes a first station 51 a for forming afiber 52 a having a film of a first bacteria killing material 53 asecured thereto. A second station 55 a includes a second fiber 56 ahaving a film of a second bacteria killing material 57 a securedthereto.

[0065] Similar to the method of FIG. 8, the fibers are then directedinto a third station 58 a that weaves the fibers into a porous filtermedium 59 a comprised of fibers with a film of a first bacteria killingmaterial thereon and fibers with a film of a second bacteria killingmaterial thereon which are located in proximity to each other to therebyprovide the bacteria killing action from two different bacteria killingmaterials.

[0066] Also similar to the embodiment of FIG. 8, filter medium 59 a ofFIG. 8A is also used as a carrier for first bacteria killing material 53a and second bacteria killing material 57 a which are secured thereon toprovide a controlled release so that water passing through filter medium59 a not only removes debris removed but also the bacteria is killed bythe bacteria killing materials located on filter medium 59 a.

[0067] While bacteria killing materials are shown, other waterpurification materials such as algaecides, clarifier, etc . . . can beused. In addition the water purification materials can be embedded inthe fibers rather than secured to the exterior of the fibers.

[0068]FIG. 9 is a top view a filter cartridge 70 and FIG. 10 is asectional exploded view of filter cartridge 70 taken along lines 10-10.Filter cartridge 70 includes a top cap member 71 and a bottom cap member72 with a rigid core tube 73 that connects top cap member 71 to bottomcap member 72. A filter medium 75, which is arranged in an annular shapewith a series of pleats that extend circumferentially around theexterior of filter cartage 70. Located between core tube 73 is anannular carrier that is impregnated with a water purification materialand more particularly to a bacteria killing material that controllablyreleases metal ions into water flowing through filter medium 75 tothereby effectively kill bacteria. In the present embodiment, carrier 77can be form from either a rigid or flexible material.

[0069] Thus the embodiment shown in FIG. 10 comprises a dual filterapparatus for water purification including water purification forpotable water as well as for a swimming pool, hot tub or spa with thefilter medium 75 comprising a network of openings therein to enablewater to flow therethrough while retaining waste particles. The bacteriakilling material, is dispersibly secured in an annular carrier insert 77proximate the filter medium 75. The bacteria killing material isreleasable over time so that the flow path of water through and aroundannular carrier insert 77 kills bacteria therein while the filter medium75 removes waste particles to thereby enable the dual filter apparatusto simultaneously remove waste particles and kill bacteria. By havingthe insert 77 attached to the filter cartridge 70 one can simultaneouslyreplace the bacteria killing material and the filter cartridge. However,if desired the insert could be separately replaceable. Although insert77 is shown attached to filter cartridge it is envisioned that insert 77could also be placed directly in the line leading to or away from thefilter housing or on the inside of the filter housing and proximate theoutside of the filter.

[0070]FIG. 10A is similar to FIG. 10 except that cartridge filter 70 ais shown having an annular carrier insert 77 a containing purificationmaterial engaging the exterior surface of the rigid core tube 73 offilter cartridge 70 a. In the present embodiment, annular carrier insert77 a may be made from an elastic or flexible material with the waterpurification material held thereon through adhesion or physicalcontainment thereof.

[0071] In the operation of the filter medium of FIGS. 10 and 10A, waterflows through the openings of filter medium 75 while the debrisparticles present in the water encounter the external network of filtermedium 75 where they are screened off and prevented from flowing throughfilter medium 75. In FIG. 10, after the water is filtered by filtermedium 75, the water then engages annular sleeve 77 where purificationmaterials present in the sleeves are released to purify the water. InFIG. 10A, after the water is filtered by filter medium 75, the waterthen engages annular sleeves 77 a where purification materials presentin the sleeves are released to purify the water. One way of purifyingthe water would be by releasing materials that kill bacterial and viralagents that are present in the filtered water.

[0072]FIG. 10B is a view similar to FIG. 10 except that a cartridgefilter 70 b is shown having an annular carrier 77 b carrying a waterpurification material with the carrier engaging the exterior surface ofthe filter cartridge 70 b. Exterior placement of carrier 77 b allows oneto replace the carrier and spent water purification materials withoutreplacing the filter cartridge.

[0073] In the operation of the filter cartridge of FIG. 10B, water flowsthrough the openings of annular carrier insert 77 b while large debrisparticles present in the water encounter the external network of annularcarrier insert 77 b where they are screened off and prevented fromflowing through the annular carrier insert. For example, as water flowsthrough the annular carrier insert 77 b, various water purificationmaterials present within insert 77 b are released to kill bacterial andviral agents that are present in the water. Once the water passesthrough insert 77 b, the water is then filtered by filter medium 75before the water enters into core 73. The filter medium 75 is capable ofscreening out smaller debris particle that were able to pass through thenetwork of annular carrier insert 77 b.

[0074]FIGS. 11 and 11A are perspective views of a porous annular filtersleeve, the sleeves containing a water purification material. FIG. 11shows a porous filter sleeve 80 that has been formed from a single pieceof flexible material with the material containing a sonic weld 81 thatholds the material in an annular shape. The single piece of material canform an external sleeve for dispersibly carrying the bacteria killingmaterial. That is, the sleeve 80 includes a porous material that screensout debris while letting water through with a bacteria killing materialdispersibly secured thereto. The bacteria killing material iscontrollable releasable as water flows through the filter sleeve.

[0075]FIG. 11A shows a one-piece porous annular filter sleeve 80 a thatcan either be formed from a rigid material or formed from elastic orflexible material. Similar to filter sleeve 80, annular filter sleeve 80a includes a porous material that screens out debris while allowingwater through. It should be pointed out that the screening performed bythe sleeve 80 a is a secondary screening in that the primary screeningis performed by the filter cartridge that supports the filter sleeve. Inthe embodiment shown filter sleeve 80 a contains a water purificationmaterial such as a bacteria killing material dispersibly secured theretoand is controllably releasable as water flows through the filter sleeve.

[0076] When formed from a sheet of elastic or flexible material, filtersleeve 80 a can be placed around a filter cartridge such as shown inFIG. 10B, around a filter medium as shown in FIG. 22, or around a filtercartridge core as shown in FIG. 10A, to provide in situ release of waterpurification material.

[0077] In operation, filter sleeves 80 and 80 a can be placed on theoutside of a filter cartridge to release water purification materialssuch as bacteria killing materials to water flowing through the filtercartridge. By placing the proper size sleeve on the cartridge a user canon an after market basis match the life of the filter medium as ascreener of waste particles to the amount of bacteria killing materialnecessary to kill bacteria during the useful life of the filter so thatthe filter can simultaneously screen waste particles and kill bacteriato provide a dual water filter apparatus.

[0078] If desired the sleeve can be spaced from the filter medium so asto permit exchange of the filter medium without removing the sleeve withthe water purification. Also the water purification material can beapplied to an inner surface of housing of the cartridge or a sleeve topermit one to achieve independence between the life of the waterpurifier and the live of the filter medium.

[0079]FIG. 12 is a pictorial exploded view of filter cartridge 70showing the filter core tube 73 with openings 73 therein for flow ofwater therethrough. Positioned next to core tube 73 is annular poroussleeve 77 that carries a water purification material dispersed thereinthat becomes an integral part of the filter. That is annular sleeve 77sits between core tube 73 and annular filter medium 75. A set of bands75 a is located in a spaced condition around the periphery of filtermedium 75 to maintain the integrity of the filter medium.

[0080]FIG. 13 is a partial schematic view of a system for waterpurification wherein debris and bacteria are simultaneously removed by areplaceable cartridge. The water purification system includes acontainer 85 for holding water to be purified. An outlet 86 directswater to filter housing 88 wherein a cartridge filter 89 having a filtermedium with a bacteria killing material secured thereto is located. Acap 90 is placed onto top of container 88 to hold filter cartridge 89therein. The water circulates back into container 85 through conduit 87.Thus it can be envisioned that the system is suitable for waterpurification of potable water as well as swimming pools, hot tubs orspas, which need to maintain the water free of debris as well as free ofharmful bacteria.

[0081] While the ion yielding material is shown mechanical secured tothe filter medium or an insert through an adhesive it is envisioned thatin certain types of filters the ion yielding materials could beintegrally formed into a portion of a filter medium or a water cartridgehousing such as an end cap or the filter core. Thus it is envisionedthat the water purification material which is yieldable in the presenceof water can be carried either within a porous structure of the housingor a porous structure of the filter medium or dispersibly secured to thefilter medium so that the water purification material can be released aswater contacts the housing.

[0082] Thus in one embodiment of the invention the invention comprises awater filter structure that minimizes obstruction to normal flow throughthe filter housing. The housing including at least a portion thereincontaining a water treatment composition that yields a water treatmentcomposition material in the presence of water. A filter medium securedto the cartridge has a network of openings sufficiently large to allowwater to flow therethrough but sufficiently small to prevent wasteparticles from flowing therethrough so that when water flows through thehousing the water treatment composition performs an action to the waterwhile the filter medium screens out waste particles from the water.Examples of water treatment compositions that perform an action includealgaecides, bactericide, clarifiers, pH adjusters (for example,limestone) and foam suppressants.

[0083] FIGS. 14 show a partial cross-sectional view of water filtercartridge 91 and FIG. 15 show a partial cross-sectional view of waterfilter cartridge 91 a. Each of the cartridges is shown having a top capmember 92, a bottom cap member 93, a filter medium 95 a water filtercartridge core 94. Filter cartridge 91 has a water purification materialcarrier 96 located within the water filter cartridge core 94 for thetime controlled releasing of water purification material into the water.Similarly, filter cartridge 91 a has a water purification materialcarrier 97 located within the water filter cartridge core 94 for thetime controlled releasing of water purification material into the water.

[0084] The water purification material carrier 96 of FIG. 14 comprises anon-woven fibrous material located within water filter cartridge core 94of filter cartridge 91. The fibrous material can be made from a varietyof materials including rubber, plastic and metal. The fibrous materialcan be coated with a water purification material or the waterpurification material can be impregnated into the fibrous material.

[0085] The water purification material carrier 97 of FIG. 15 is locatedwithin water filter cartridge core 94 of the filter cartridge 91 a andcomprises water purification materials 97 b, which are located either oncarrier 97 or within an interior of an annular sleeve 97 a. Carrier 97can be made from various materials such as plastic, or metal andincludes openings or pores therein to permit water to contact thepurification material. If desired openings 97 c can be provided foringress and egress of water through carrier 97. The openings should besufficiently small to retain the water purification material thereinwhen it is in a ready to use condition.

[0086] Purification material carriers 96 and 97 can either bepermanently installed within water filter cartridge core 94 so as to bereplaceable with the filter medium 95 or are separately replaceable oncetheir purification material has been depleted.

[0087] In the replaceable form, the steps for the replacement of thewater purification material comprises (1) removing the top cap member 92or bottom cap member 93 from the filter cartridge 91; (2) removing thedepleted water purification material from water filter cartridge core94; (3) inserting a fresh water purification material within the filtercartridge core 94; and (4) attaching the cap member back on the filtercartridge 91.

[0088] In normal operation of the filter cartridges of FIGS. 14 and 15,filter cartridge 91, 91 a allow for the flow of water through theopenings of filter medium 95 while simultaneously preventing debrisparticles present in the water from flowing therethrough. Once throughfilter medium 95, the filtered water flows into the filter cartridgecore 94 where the water engages the water purification material carrierto thereby release the water purification materials. For example, onepurifies the water by killing contaminates such as bacteria, viruses,and algae that are present in the filtered water.

[0089]FIG. 16 is a pictorial exploded view of a filter medium 98 havinga hollow water porous core 99 located within the interior of filtermedium 98 and containing at least one water purification material 100dispensed thereon. In the present embodiment, the hollow core 99 can bemade from a variety of materials including rubber, plastic and metal.After water porous core 99 is formed, water purification material 100 isthen coated onto the surface 99 a of the filter water porous core 99.Alternatively, water porous core 99 may also be formed from an adhesivemixed with or containing the water purification material 100. Althoughthe core is described as water porous it is envisioned that the coreneed not be water porous if the normal circulation of water through thefilter is not curtailed. For example, a core 99 having a length lessthan the length of the cartridge filter medium would allow normal aswater could flow past the core carrier without having to flow thoroughthe core carrier

[0090]FIG. 17 shows a partial cross-sectional view of a pleated filtermedium 101 having a hollow porous core 102 located within an interior ofthe filter medium 101. As shown in FIG. 17, pleated filter medium 101has an interior surface 103 with purification materials 105 such as abactericide like silver chloride dispersibly secured thereto forpurifying water that enters through filter member 101.

[0091]FIG. 18 is similar to FIG. 17 except that the purificationmaterial is secured to the interior surface 103 of pleated filter medium101 in the form of an elongated member 106. Although FIG. 18 showselongated member 106 held proximate to the interior surface 103 of thepleated filter medium 101 by a wire hook 107, elongated member 106 canalso be secured to filter medium 101 in alternative ways such as by astitching, and by an adhesive.

[0092] In the operation of the filter medium of FIGS. 17 and FIG. 18,water flows through the openings of pleated filter medium 101 whiledebris particles present in the water encounter the external network ofthe filter medium 101 where they are screened off and prevented fromflowing through filter medium 101. As water flows through the filtermedium of FIG. 17, purification materials 105, located on the interiorsurface 103 of filter medium 101, are released to purify the water.Similarly, as water flows through the filter medium of FIG. 18, thewater purification material 106 is released. Releasing a material forkilling of bacterial and viral agents that are present in the filteredwater allows one to both purify the water and remove debris from thewater. It should be understood that filter cartridges can be used forscreening debris by flow in either flow direction i.e. radial inwardflow or radial outward flow. In order to minimize the effect of debrison the water purification materials the water purification materials canbe placed on the downstream side of the filtering section so that thefiltered water is purified rather than the non-filtered water.

[0093]FIG. 18A shows a perspective view of pleated filter medium 101having a plurality of cylindrical elongated members 106 containing waterpurification materials. The members are held proximate to the exteriorsurface 104 of the pleated filter medium 101 by a wire hook 107. Similarto FIG. 18, although elongated member 106 is shown held proximate to theexterior surface 104 of pleated filter medium 101 by wire hook 107,elongated member 106 can also be secured to the filter medium 101 inother ways including by a stitching, and by an adhesive.

[0094] Although FIG. 18A shows the use of a plurality of elongatedmembers secured between the pleats of the filter medium 101, the numberof elongated members that are secured to the filter medium 101 may varyfrom as little as one elongated member to a plurality of elongatedmembers, depending on the user's needs. When more than one elongatedmember is secured to the filter medium 101, each elongated member maycontain the same purification material 101, or a different purificationmaterial, depending on the user's needs and desires.

[0095]FIG. 19 is similar to FIG. 17 except interior surface 103 ofpleated filter medium 101 are shown supporting an adjustable waterpurification material dispenser 108. Although two adjustable waterpurification material dispensers are shown in the present embodiment,alternative embodiments of filter medium 101 can have one dispenser to aplurality of dispensers, depending on the user's needs. In embodimentsin which there are more than one adjustable water purification materialdispensers, chamber 109 of the purification material dispensers 108 mayeither carry the same water purification material or different types ofwater purification materials from each other or the combination ofdifferent purification material, again, depending on the user's needs.For example, the adjustable water purification material dispensers ofthe present embodiment may both carry the same water purificationmaterial such as silver chloride or one may carry silver chloride whilethe other carry a different water purification material such as analgaecide.

[0096]FIG. 19A is a close-up view of adjustable water purificationmaterial dispenser 108 of FIG. 19. Purification material dispenser 108includes a chamber 109 for storing purification materials 111. Chamber109 of the present dispenser is sufficiently flexible so as to be ableto support water purification materials of various shapes and sizesincluding water purification materials form in the shape of pellets,sticks, and strips. Purification material dispenser 108 also includes asecond chamber 110 for the time controlled releasing of purificationmaterials 111. As shown in FIG. 19A, a plurality of openings 109 b individer 109 a permit ingress and egress of water into chamber 109. Alsoa plurality of outlet walls 110 a containing a plurality of openings 110b allowing for the flow of water therethrough. Thus in the embodimentsshown in FIG. 19a two separate compartments are provided for twodifferent water unification materials with fluid ingress and egresspermitted to both compartments. Located on an exterior surface ofpurification material dispenser 108 is a slideable sleeve 108 a forselectively blocking off water flow through outlet openings 110 b.Sleeve 108 is used to control the amount of water that enterspurification material dispenser 108 thereby controlling the amount ofwater purification material that purification material dispenser 108releases.

[0097] In the operation of dispenser 108, water first enters outlet 110by flowing through the outlet openings 110 b of outlet walls 110 a thatare not cover by sleeve 108 a. Water then enters chamber 109 throughopenings 109 b of divider 109 a and interacts with purificationmaterials 111. The interaction between the water and purificationmaterial 111 allows a portion of purification material 111 to bereleased into the water. After a portion of purification material 111has been released into the water, the purification material is thencarried by the water out of chamber 109 through openings 109 b ofdivider 109 a and out of outlet 110 by way of outlet openings 110 b. Tocontrol the amount of water purification material that is release bydispenser 108, a user simply slides sleeve 108 a to cover more or tocover less outlet openings 110 b of outlet walls 110 a, therebycontrolling the amount of water flowing into and out of dispenser 108.

[0098]FIG. 19B shows a partial cross-sectional view of an alterativewater purification material dispenser 119. Purification materialdispenser 119 is defined by a plurality of walls 120, each of the walls120 having a plurality of openings 121 allowing for the flow of watertherethrough. Located within purification material dispenser 119 is awater purification material supporting chamber 122 for holding a waterpurification material 123, the water purification materials being largerthan the openings to retain the undissolved water purification materialtherein. As water flows through the chamber the water purificationmaterials are released to purify the water.

[0099] In the operation of purification material dispenser 119, waterpasses into chamber 122 by way of openings 121. Once in chamber 122, thewater interacts with purification material 123. The interaction betweenthe water and the purification material 111 allows a portion ofpurification material 123 to be released into the water. After a portionof purification material 123 has been released into the water, the waterthen carries the purification material out of chamber 122 throughplurality of openings 121.

[0100]FIG. 20 is similar to FIG. 19 but with the hollow water porouscore 102 coated with water purification material 112. In FIG. 20, thewater purification material 112 coated on core 102 may either be thesame as the water purification materials 111 that are located in thechamber 109 of the adjustable water purification material dispensers 108or alternatively, may be of a different water purification material.

[0101] In the operation of the embodiment of FIG. 20, water flowsthrough the openings of the exterior surface 104 of pleated filtermedium 101 while the debris particles present in the water encounter theexternal network of the filter medium 101 where they are screened offand prevented from flowing through the filter medium 101. As water flowsthrough the interior surface 103 of filter medium 101, the waterencounters the adjustable water purification material dispensers 108.Purification materials 111 present within chamber 109 of dispensers 108move to outlet 110 where they are then released to purify the water.

[0102] In the embodiment of FIG. 20, after the water has been purifiedby water purification material 111, the water then moves through filtermedium 101 to reach the water porous core 102 where a second waterpurification material 112, located on the core 102, is dispensed tofurther purify the water as the water flows through openings in thecore.

[0103]FIG. 21 shows a mesh screen 114 coated with a water purificationmaterial 115 and engaging the exterior of a filter medium 113. The meshscreen 114 can be made from a variety of materials including plastic andmetal.

[0104] Mesh screen 114 contains a plurality of openings for screeningwaste particles of larger size from the water. In normal operation ofmesh screen 114, large debris particles encounter the external networkof mesh screen 114 where they are screened out while water is allowed toflow therethrough. As water flows through mesh screen 114, the waterpurification materials 115 are time controllably released from the meshscreen to purify the water, such as by killing bacterial and viralorganisms. The water is then further screened of debris by flowingthrough the filter medium 113, which prevents the smaller debris thatwere able to flow through the network of the mesh screen from flowingthrough filter medium 113. Since filter medium 113 only has the job ofscreening out the smaller debris particles present in the water, the useof the screen mesh can extend the life of filter medium 113.

[0105]FIG. 22 is a pictorial exploded view showing a filter medium 116having an annular water porous sleeve 117 containing a waterpurification material 118 engaging the exterior surface of the filtermedium 116. Although annular sleeve 117 may be of a rigid material, itis preferred that the annular water porous sleeve of the presentembodiment be made of an elastic or flexible material.

[0106] The method of operation of the for the embodiment of FIG. 22 isvery similar to the method of operation for the embodiment of FIG. 21 inthat water and smaller debris particles are allowed to flow through theopenings of annular sleeve 117 while larger debris particles encounterthe external network of sleeve 117 where they are prevented from flowingtherethrough. As water flows through sleeve 117, water purificationmaterials 118 are time controllably released to purify the water. Thepurified water is then further filtered of debris by flowing through thefilter medium 116, which prevents the smaller debris that were able toflow through sleeve 117 from flowing through the filter medium 116.Since the filter medium 116 only has to screen the smaller debris, theuse of the annular water porous sleeve 117 will extend the life of thefilter medium 116 as well as purify the water.

[0107] Depending on the size of the openings for annular sleeve 117,annular sleeve 117 may alternatively be used as an ultra-purificationsystem in which the openings of annular sleeve 117 may be sufficientlysmall to not only screen out the larger debris but also the smallerdebris. Once screened by annular sleeve 117, the water would then bescreened for a second time by filter medium 116 to remove small debristhat was missed by the annular sleeve 117.

[0108] While the present invention has been described in relation towater treatment materials the present invention is also suitable forother fluid activators while performing the debris screening process. Byactivators it is meant to include other materials that are added to afluid to change some characteristic of the fluid and could include forexample chemicals or the like that react with foreign particles in thefluid to render the foreign particles harmless. A feature of the presentinvention when used with activators that kill organisms that grow on thefilter is that the life of the filter is extended by avoiding the buildup of bacteria or other organisms on the filter which would normallyaccumulate and shorten the life of the filter. Thus, with the presentinvention one can produce a multiple purpose filter medium for screeningout debris particles, with the filter medium having an exterior surfaceand an interior surface; and an activator, which could be liquid orsolid or both that can be retained by the filter medium to thereby allowthe filter medium to in situ screen out debris while at the same timethe activator acts on the fluid that flows through the filter medium.

[0109] While the activator or water purification material can be held onthe surface of the filter medium in some applications it may be desirousto maintain the purification material within the pores of the filtermedium.

[0110] As an alternate method of securing the water treatment materialor activators in the fluid stream one can apply the activator as onewould apply paint to a surface. This procedure of stroking or sprayingthe activator on a surface allows one to on-site refurbish a filter thatmay be spent. This procedure eliminates the need for a separate carrierfor the water purification materials as.

I claim:
 1. A method of making a dual filter for in situ waterpurification that minimizes obstruction to normal flow through a filterhousing comprising: weaving a first fiber with a second fiber to form aporous filter medium for allowing water therethrough but for preventingwaste particles from flowing therethrough; and securing a controllablerelease water purification material to said filter medium to enable saiddual filter medium to simultaneously screen waste particles from a watersource and purify water that come into contact with water purificationmaterial.
 2. The method of claim 1 wherein the step of securing thereleasable water purification material comprises securing a firstreleasable water purification material to the first fiber and securing asecond releasable water purification material to the second fiber. 3.The method of claim 2 wherein the steps of securing the first waterpurification material to the first fiber and securing the second waterpurification material to the second fiber comprises dispersibly securingthe first water purification material to the first fiber and dispersiblysecuring the second water purification material to the second fiber. 4.The method of claim 2 wherein the steps of securing the first waterpurification material to the first fiber and securing the second waterpurification material to the second fiber comprises securing a film ofthe first water purification material to the first fiber and securing afilm of the second water purification material to the second fiber. 5.The method of claim 2 wherein the steps of securing the first waterpurification material to the first fiber and securing the second waterpurification material to the second fiber comprises securing a firstbacteria killing material to the first fiber and securing a secondbacteria killing material to the second fiber.
 6. The method of claim 5wherein the steps of securing a first bacteria killing material to thefirst fiber and securing a second bacteria killing material to thesecond fiber comprises securing a first metal ion yielding material tothe first fiber and securing a second metal ion yielding material to thesecond fiber.
 7. A dual water purification apparatus for a swimmingpool, hot tub or spa that minimizes obstruction to normal flow throughthe filter housing comprising: a filter cartridge, said filter cartridgehaving a porous filter medium for filtration removal of waste particlesfrom water flowing through said porous filter medium; a waterpurification material, said water purification material dispersiblysecured to a carrier, said carrier placeable in a flow path through saidfilter cartridge medium, said water purification material controllablyreleasable so that a flow of water through said filter medium purifiesthe water therein while the porous filter medium removes waste particlesto thereby enable the dual filter to simultaneously screen debrisparticles and purify water in said filter cartridge over an extendedperiod of time.
 8. The dual water purification apparatus of claim 7wherein the carrier comprises a screen for engaging an exterior surfaceof the filter cartridge.
 9. The dual water purification apparatus ofclaim 7 wherein the carrier comprises an insert placeable within thecore opening of said filter cartridge.
 10. The dual water purificationapparatus of claim 9 wherein the insert contains the water purificationmaterial located within an interior space of the insert.
 11. The dualwater purification apparatus of claim 7 wherein the carrier is a rigidannular water porous insert.
 12. The dual water purification apparatusof claim 11 wherein the annular insert is located between a core of thefilter cartridge and the filter medium of the filter cartridge.
 13. Thedual water purification apparatus of claim 7 wherein the carriercomprises an annular member placeable around an exterior of said filtercartridge.
 14. The dual water purification apparatus of claim 13 whereinthe annular member comprises an elastic material.
 15. The filtercartridge of claim 7 wherein the carrier comprises a non-woven fibrousmaterial.
 16. The filter cartridge of claim 15 wherein the carriercomprises a rubber, plastic or metal.
 17. A filter medium comprising: afirst fiber; a first water purification material for purifying water,said first water purification material secured to said first fiber; asecond fiber; and a second water purification material for purifyingwater, said second water purification material secured to said secondfiber, said fibers extending about each other to form a sheet of porousmaterial for screening out debris particles present in the water, saidporous material containing said first water purification material andsaid second water purification material for purifying water that flowstherethrough while simultaneously filtering out debris present in thewater.
 18. The filter medium of claim 17 wherein the purificationmaterials are dispersibly secured to said fibers so as to minimizeobstruction to normal flow of water through the sheet of porousmaterial.
 19. The filter medium of claim 17 wherein the purificationmaterials are secured directly to the fibers by a thin film of non-watersoluble porous adhesive in a condition to allow a controlled release ofthe purification materials.
 20. The filter medium of claim 17 whereinthe first water purification material and the second water purificationmaterial are the same water purification material.
 21. The filter mediumof claim 17 wherein the first water purification material and the secondwater purification material are different water purification material.22. The filter medium of claim 21 wherein the first water purificationmaterial is a first metal ion yielding material and the second waterpurification material is a second metal ion yielding material.
 23. Thefilter medium of claim 21 wherein the first water purification materialis a silver chloride and the second water purification material is analgaecide.
 24. The filter medium of claim 17 wherein the porous materialcomprises an elastic material.
 25. The filter medium of claim 17 whereinthe sheet of porous material has an annular shape.
 26. The filter mediumof claim 25 wherein the porous material comprises a rigid material. 27.As multiple purpose filter medium comprising: a filter medium forscreening out debris particles, said filter medium having an exteriorsurface and an interior surface; and a water purification material forpurifying water, said water purification material located on said filtermedium to thereby allow said filter medium to in situ screen out debriswhile simultaneously purifying water that flows through said filtermedium.
 28. The multiple purpose filter medium of claim 27 wherein thewater purification m0aterial is dispersibly secured to said filtermedium.
 29. The multiple purpose filter medium of claim 27 wherein thewater purification material is secured to the interior surface of saidfilter medium.
 30. The multiple purpose filter medium of claim 27wherein the water purification material is secured to the exteriorsurface of said filter medium.
 31. The multiple purpose filter medium ofclaim 27 wherein the water purification material secured to the filtermedium are in the form of an elongated member.
 32. The multiple purposefilter medium of claim 27 including an adjustable water purificationmaterial dispenser located on the interior surface of said filtermedium, said dispenser having chamber for storing and an outlet forcontrollably releasing said water purification material.
 33. Themultiple purpose filter medium of claim 27 including a plurality ofadjustable w0ater purification material dispensers located on theinterior surface of said filter medium for controllably releasing saidwater purification material.
 34. The multiple purpose filter medium ofclaim 33 wherein each of said adjustable water purification materialdispensers contain a different water purification material.
 35. Themultiple purpose filter medium of claim 33 wherein each of saidadjustable water purification material dispenser contains a metalion-yielding material.
 36. The multiple purpose filter medium of claim33 wherein at least one of said adjustable water purification materialdispensers contains a silver chloride ion.
 37. The multiple purposefilter medium of claim 33 including a second purification materialdispersibly secured to said filter medium to further purify said water.38. The multiple purpose filter medium of claim 37 wherein thepurification material dispersibly secured to said filter medium is asilver chloride ion-yielding material.
 39. The multiple purpose filtermedium of claim 37 wherein the filter medium comprises a mesh screen.40. The multiple purpose filter medium of claim 39 wherein the meshscreen comprises of plastic.
 41. A multiple purpose filter mediumcomprising: a filter medium for screening out debris particles, saidfilter medium having an exterior surface and an interior surface; and anactivator retained by said filter medium to thereby allow said filtermedium to in situ screen out debris while simultaneously acting on thefluid that flows through said filter medium.
 42. The multiple purposefilter medium of claim 41 wherein the fluid activator is a waterpurification material.
 43. The multiple purpose filter medium of claim42 wherein the fluid activator is an ion generating material.
 44. Themultiple purpose filter medium of claim 41 wherein the activator issecured to the filter medium.